Resumen del autor, extraído del trabajo. As the petroleum industry enters the 21st century, a staggering level of exploration and production investment will be needed to satisfy increasing worldwide demand, given the maturity of large producing fields. Pressures on reducing finding, development and production costs will continue to mount with a strong need for enhancing total asset value. The magnitude of the task ahead far surpasses the impact of gains in oilfield efficiency achieved over the past decade, and will require a new generation of leading-edge technology, highly skilled professionals and a more effective petroleum business structure involving new roles for oil and gas companies and service companies. This paper describes the transformation of the petroleum service sector over the past 15 years, and outlines the evolution of the technology development and commercialization process that has resulted from greater outsourcing to service companies. The benefits derived from successful alliances between the two sectors are documented by specific examples. While the industry is progressing in its ability to structure viable, long-term arrangements, future challenges dictate a major shift in approach. A new, potentially more effective business model is proposed, whereby the relationship between oil and gas companies and service companies is taken to a new level of team synergy. This "Joint Value Enhancement" model provides a foundation for integrated reservoir optimization. Successful implementation depends on taking full advantage of internet-based workspace knowledge, while maintaining the core businesses of petroleum and service companies distinct and separate.